The moose population on a small island is observed to be given by the function

P(t) = 120 t - 0.4 t^4 + 900

wheret is the time (in months) since observations of the island began.

** Note: ** you can get a larger view of the graph by clicking on it

where

(a) The maximum population attained at

The maximum population is

(b) When does the moose population disappear from the island?

You can earn partial credit on this problem.